Modern papers

During the last two or three decades, a great effort has been made to improve our knowledge on the sunspot number. Here, we list some interesting papers (and some books) related to this issue.

 

Topical Issue (Solar Physics journal, 2016): Recalibration of the Sunspot Number

  • Clette, F., Cliver, E.W., Lefèvre, L., Svalgaard, L., Vaquero, J.M., Leibacher, J.W. Preface to Topical Issue: Recalibration of the Sunspot Number. Solar Physics (2016) 291: 2479. (doi)
  • Stenflo, J.O. Transition of the Sunspot Number from Zurich to Brussels in 1980: A Personal Perspective. Solar Physics (2016) 291: 2487. (doi)
  • Carrasco, V.M.S., Vaquero, J.M. Sunspot Observations During the Maunder Minimum from the Correspondence of John Flamsteed. Solar Physics (2016) 291: 2493. (doi)
  • Friedli, T.K. Sunspot Observations of Rudolf Wolf from 1849 – 1893. Solar Physics (2016) 291: 2505. (doi)
  • Willis, D.M., Wild, M.N., Warburton, J.S. Re-examination of the Daily Number of Sunspot Groups for the Royal Observatory, Greenwich (1874 – 1885). Solar Physics (2016) 291: 2519. (doi)
  • Willis, D.M., Wild, M.N., Appleby, G.M., Macdonald, L. T. The Greenwich Photo-heliographic Results (1874 – 1885): Observing Telescopes, Photographic Processes, and Solar Images. Solar Physics (2016) 291: 2553. (doi)
  • Curto, J.J., Solé, J.G., Genescà, M., Blanca, M. J., Vaquero, J. M. Historical Heliophysical Series of the Ebro Observatory. Solar Physics (2016) 291: 2587. (doi)
  • Lefèvre, L., Aparicio, A.J.P., Gallego, M.C., Vaquero, J.M. An Early Sunspot Catalog by Miguel Aguilar for the Period 1914 – 1920. Solar Physics (2016) 291: 2609. (doi)
  • Clette, F., Lefèvre, L. The New Sunspot Number: Assembling All Corrections. Solar Physics (2016) 291: 2629. (doi)
  • Svalgaard, L., Schatten, K.H. Reconstruction of the Sunspot Group Number: The Backbone Method. Solar Physics (2016) 291: 2653. (doi)
  • Usoskin, I.G., Kovaltsov, G.A., Lockwood, M., Mursula, K., Owens, M., Solanki, S.K. A New Calibrated Sunspot Group Series Since 1749: Statistics of Active Day Fractions. Solar Physics (2016) 291: 2685. (doi)
  • Dudok de Wit, T., Lefèvre, L., Clette, F. Uncertainties in the Sunspot Numbers: Estimation and Implications. Solar Physics (2016) 291: 2709. (doi)
  • Clette, F., Lefèvre, L., Cagnotti, M., Cortesi, S., Bulling, A. The Revised Brussels–Locarno Sunspot Number (1981 – 2015). Solar Physics (2016) 291: 2733. (doi)
  • Cliver, E.W., Ling, A.G. The Discontinuity Circa 1885 in the Group Sunspot Number. Solar Physics (2016) 291: 2763. (doi)
  • Lockwood, M., Scott, C.J., Owens, M.J., Barnard, L., Willis, D.M. Tests of Sunspot Number Sequences: 1. Using Ionosonde Data. Solar Physics (2016) 291: 2785. (doi)
  • Lockwood, M., Owens, M.J., Barnard, L., Scott, C.J., Usoskin, I.G., Nevanlinna, H. Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data. Solar Physics (2016) 291: 2811. (doi)
  • Lockwood, M., Owens, M.J., Barnard, L., Usoskin, I.G. Tests of Sunspot Number Sequences: 3. Effects of Regression Procedures on the Calibration of Historic Sunspot Data. Solar Physics (2016) 291: 2829. (doi)
  • Lockwood, M., Owens, M.J., Barnard, L. Tests of Sunspot Number Sequences: 4. Discontinuities Around 1946 in Various Sunspot Number and Sunspot-Group-Number Reconstructions. Solar Physics (2016) 291: 2843. (doi)
  • Zolotova, N.V., Ponyavin, D.I. How Deep Was the Maunder Minimum?. Solar Physics (2016) 291: 2869. (doi)
  • Cliver, E.W. Comparison of New and Old Sunspot Number Time Series. Solar Physics (2016) 291: 2891. (doi)
  • Li, K.J., Li, F.Y., Zhang, J., Feng, W. Investigation of Sunspot Area Varying with Sunspot Number. Solar Physics (2016) 291: 2917. (doi)
  • Carrasco, V.M.S., Vaquero, J.M., Gallego, M.C., Sánchez-Bajo, F. A Normalized Sunspot-Area Series Starting in 1832: An Update. Solar Physics (2016) 291: 2931. (doi)
  • Muraközy, J., Baranyi, T., Ludmány, A. An Alternative Measure of Solar Activity from Detailed Sunspot Datasets. Solar Physics (2016) 291: 2941. (doi)
  • Kopp, G., Krivova, N., Wu, C.J., Lean, J. The Impact of the Revised Sunspot Record on Solar Irradiance Reconstructions. Solar Physics (2016) 291: 2951. (doi)
  • Bertello, L., Pevtsov, A., Tlatov, A., Singh, J. Correlation Between Sunspot Number and Ca ii K Emission Index. Solar Physics (2016) 291: 2967. (doi)
  • Svalgaard, L. Reconstruction of Solar Extreme Ultraviolet Flux 1740 – 2015. Solar Physics (2016) 291: 2981. (doi)
  • Winter, L.M., Pernak, R.L., Balasubramaniam, K.S. Comparing SSN Index to X-Ray Flare and Coronal Mass Ejection Rates from Solar Cycles 22 – 24. Solar Physics (2016) 291: 3011. (doi)
  • Muscheler, R., Adolphi, F., Herbst, K., Nilsson, A. The Revised Sunspot Record in Comparison to Cosmogenic Radionuclide-Based Solar Activity Reconstructions. Solar Physics (2016) 291: 3025. (doi)
  • Carrasco, V.M.S., Aparicio, A.J.P., Vaquero, J.M., Gallego, M.C. The New Sunspot-Number Index and Solar-Cycle Characteristics. Solar Physics (2016) 291: 3045. (doi)
  • Vaquero, J.M., Svalgaard, L., Carrasco, V.M.S., Clette, F., Lefèvre, L., Gallego, M.C., Arlt, R., Aparicio, A.J.P., Richard, J.-G., Howe, R. A Revised Collection of Sunspot Group Numbers. Solar Physics (2016) 291: 3061. (doi)
  • Cortesi, S., Cagnotti, M., Bianda, M., Ramelli, R., Manna, A. Sunspot Observations and Counting at Specola Solare Ticinese in Locarno Since 1957. Sol Phys (2016) 291: 3075. (doi)
  • Baranyi, T., Győri, L., Ludmány, A. On-line Tools for Solar Data Compiled at the Debrecen Observatory and Their Extensions with the Greenwich Sunspot Data. Solar Physics (2016) 291: 3081. (doi)
  • Pötzi, W., Veronig, A.M., Temmer, M., Baumgartner, D.J., Freislich, H., Strutzmann, H. 70 Years of Sunspot Observations at the Kanzelhöhe Observatory: Systematic Study of Parameters Affecting the Derivation of the Relative Sunspot Number. Solar Physics (2016) 291: 3103. (doi)
  • Balasubramaniam, K.S., Henry, T.W. Sunspot Numbers from ISOON: A Ten-Year Data Analysis. Solar Physics (2016) 291: 3123. (doi)

 

General

  • Abreu, J.A., Beer, J., Steinhilber, F., Tobias, S.M., Weiss, N.O. For how long will the current grand maximum of solar activity persist? Geophysical Research Letters 35, article ID L20109, 2008. (doi)
  • Aguirre, L.A., Letellier, C., Maquet, J. Forecasting the Time Series of Sunspot Numbers. Solar Physics 249, 103, 2008. (doi)
  • Ahluwalia, H.S., Jackiewicz, J. Sunspot cycle 23 descent to an unusual minimum and forecasts for cycle 24 activity. Advances in Space Research 50, 662, 2012. (doi)
  • Ahluwalia, H.S. An empirical approach to predicting the key parameters for a sunspot number cycle. Advances in Space Research 53, 568, 2014. (doi)
  • Ahluwalia, H.S., Ygbuhay, R.C. Salient Features of the New Sunspot Number Time Series. Solar Physics 291, 3807, 2016. (doi)
  • Aparicio, A.J.P., Vaquero, J.M., Gallego, M.C. The proposed “Waldmeier discontinuity”: How does it affect to sunspot cycle characteristics? Journal of Space Weather and Space Climate 2, article id. A12, 2012. (doi)
  • Aparicio, A.J.P., Vaquero, J.M., Carrasco, V.M.S., Gallego, M.C. Sunspot Numbers and Areas from the Madrid Astronomical Observatory (1876 – 1986). Solar Physics 289, 4335, 2014. (doi)
  • Arlt, R. Digitization of sunspot drawings by Staudacher, in 1749-1796. Solar Physics 247:399-410, 2008. (doi)
  • Arlt, R. The solar observations at Armagh Observatory in 1795-1797. Astronomische Nachrichten 330:311, 2009. (doi)
  • Arlt, R. The solar butterfly diagram in the 18th century. Solar Physics 255:143, 2009. (doi)
  • Arlt, R. The sunspot observations by Samuel Heinrich Schwabe. Astronomische Nachrichten 332:805, 2011. (doi)
  • Arlt, R., R. Leussu, N. Giese, K. Mursula, Usoskin, I.G. Sunspot positions and sizes for 1825-1867 from the observations by Samuel Heinrich Schwabe. Mon. Not. R. Astron. Soc. 433:3165-3172, 2013. (doi)
  • Arlt, R., Weiss, N. Solar Activity in the Past and the Chaotic Behaviour of the Dynamo. Space Science Reviews 186, 525, 2014. (doi)
  • Arlt, R., Senthamizh Pavai, V., Schmiel, C., Spada, F. Sunspot positions, areas, and group tilt angles for 1611−1631 from observations by Christoph Scheiner. Astronomy & Astrophysics 595, id. A104, 2016. (doi)
  • Asensio Ramos, A. Extreme value theory and the solar cycle. Astronomy and Astrophysics 472, 293, 2007. (doi)
  • Badalyan, O.G., Obridko, V.N., Sýkora, J. Quasi-Biennial Oscillations in the North - South Asymmetry of Solar Activity. Solar Physics 247, 379, 2008. (doi)
  • Badalyan, O.G., Obridko, V.N. North-South asymmetry of the sunspot indices and its quasi-biennial oscillations. New Astronomy 16, 357, 2011. (doi)
  • Ballester, J.L., Oliver, R., Baudin, F. Discovery of the Near 158 Day Periodicity in Group Sunspot Numbers during the Eighteenth Century. The Astrophysical Journal 522, L153, 1999. (doi)
  • Ballester, J.L., Oliver, R., Carbonell, M. The periodic behaviour of the North-South asymmetry of sunspot areas revisited. Astronomy and Astrophisics 431, L5, 2005. (doi)
  • Balmaceda, L., Krivova, N.A., Solanki, S.K. Reconstruction of solar irradiance using the Group sunspot number. Advances in Space Research 40, 986, 2007. (doi)
  • Balmaceda, L.A., Solanki, S.K., Krivova, N.A., Foster, S. A homogeneous database of sunspot areas covering more than 130 years. Journal of Geophysical Research 114, article ID A07104, 2009. (doi)
  • Balogh, A., Hudson, H.S., Petrovay, K., von Steiger, R. Introduction to the Solar Activity Cycle: Overview of Causes and Consequences. Space Science Reviews 186, 1, 2014. (doi)
  • Balthasar, H. Rotational periodicities in sunspot relative numbers. Astronomy and Astrophysics 471, 281, 2007. (doi)
  • Bankoti, N.S., Joshi, N.C., Pande, S., Pande, B., Pandey, K. North-south asymmetry of different solar activity features during solar cycle 23. New Astronomy 15, 561, 2010. (doi)
  • Baranyi, T., Király, S., Coffey, H.E. Indirect comparison of Debrecen and Greenwich daily sums of sunspot areas. Monthly Notices of the Royal Astronomical Society 434, 1713, 2013. (doi)
  • Barnard, L., Lockwood, M., Hapgood, M.A., Owens, M.J., Davis, C.J., Steinhilber, F. Predicting space climate change. Geophysical Research Letters 38, article ID L16103, 2011. (doi)
  • Bazilevskaya, G.A., Cliver, E.W., Kovaltsov, G.A., Ling, A.G., Shea, M.A. Smart, D.F., Usoskin, I.G. Solar Cycle in the Heliosphere and Cosmic Rays. Space Science Reviews 186, 409, 2014. (doi)
  • Benestad, R.E. A review of the solar cycle length estimates. Geophysical Research Letters 32, article ID L15714, 2005. (doi)
  • Berghmans, D., Clette, F., Cugnon, P., Gabryl, J.-R., Hochedez, J.-F., Van der Linden, R.A.M., Verwichte, E. The solar influences data analysis centre. Journal of Atmospheric and Solar-Terrestrial Physics 64, 757, 2002. (doi)
  • Bhatt, N.J., Jain, R., Aggarwal, M. Prediction of the Maximum Amplitude and Timing of Sunspot Cycle 24. Solar Physics 260, 225, 2009. (doi)
  • Brajša, R., Wöhl, H., Hanslmeier, A., Verbanac, G., Ruždjak, D., Cliver, E., Svalgaard, L., Roth, M. On solar cycle predictions and reconstructions. Astronomy and Astrophysics 496, 855, 2009. (doi)
  • Broomhall, A.-M., Chaplin, W.J., Elsworth, Y., Fletcher, S.T., New, R. Is the Current Lack of Solar Activity Only Skin Deep? The Astrophysical Journal Letters 700, L162, 2009. (doi)
  • Cameron, R., Schüssler, M. A Robust Correlation between Growth Rate and Amplitude of Solar Cycles: Consequences for Prediction Methods. The Astrophysical Journal 685, article id. 1291, 2008. (doi)
  • Carbonell, M., Terradas, J., Oliver, R., Ballester, J.L. The statistical significance of the North-South asymmetry of solar activity revisited. Astronomy and Astrophysics 476, 951, 2007. (doi)
  • Carrasco, V.M.S., Vaquero, J.M., Gallego, M.C. A Critical Comment on the Claimed Relation between the Solar Maximum Amplitude and Max-Max Cycle Length. The Astronomical Journal 144, article id. 69, 2012. (doi)
  • Carrasco, V.M.S., Vaquero, J.M., Gallego, M.C., Trigo, R.M. Forty two years counting spots: solar observations by D.E. Hadden during 1890-1931 revisited. New Astronomy 25:95-102, 2013. (doi)
  • Carrasco, V.M.S., Vaquero, J.M., Aparicio, A.J.P., Gallego, M.C. Sunspot Catalogue of the Valencia Observatory (1920 – 1928). Solar Physics 289, 4351, 2014. (doi)
  • Carrasco, V.M.S., Villalba Álvarez, J., Vaquero, J.M. Sunspots During the Maunder Minimum from Machina Coelestis by Hevelius. Solar Physics 290, 2719, 2015. (doi)
  • Carrasco, V.M.S., Villalba Álvarez, J., Vaquero, J.M. Improving sunspot records: observations in 1728-1729 by JF Weidler. The Observatory 135, 257, 2015.
  • Carrasco, V.M.S., Lefèvre, L., Vaquero, J.M., Gallego, M.C. Equivalence Relations Between the Cortie and Zürich Sunspot Group Morphological Classifications. Solar Physics 290, 1445, 2015. (doi)
  • Carrasco, V.M.S., Villalba Álvarez, J. The heliographic latitude of the sunspot of 1676 June. The Observatrory 136, 292, 2016.
  • Carrasco, V.M.S., Vaquero, J.M., Gallego, M.C. Revisiting the prediction of solar activity based on the relationship between the solar maximum amplitude and max–max cycle length. Advances in Space Research 59, 379, 2017. (doi)
  • Casas, R., Vaquero, J.M., Vazquez, M. Solar Rotation in the 17th century. Solar Physics 234, 379, 2006. (doi)
  • Casas, R., Vaquero, J.M. The Sunspot Catalogues of Carrington, Peters, and de la Rue: Quality Control and Machine-readable Versions. Solar Physics 289:79–90, 2014. (doi)
  • Casas, R., Vaquero, J.M. The Solar Rotation in the Period 1853 – 1870 from the Sunspot Catalogues of Carrington, Peters, and de la Rue. Solar Physics 290, 2189, 2015. (doi)
  • Chapman, G.A., de Toma, G., Cookson, A.M. An Observed Decline in the Amplitude of Recent Solar-Cycle Peaks. Solar Physics 289, 3961, 2014. (doi)
  • Choudhuri, A.R., Karak, B.B. Origin of Grand Minima in Sunspot Cycles. Physical Review Letters 109, article id. 171103, 2012. (doi)
  • Chowdhury, P., Khan, M., Ray, P.C. Short-Term Periodicities in Sunspot Activities During the Descending Phase of Solar Cycle 23. Solar Physics 261, 173, 2010. (doi)
  • Chowdhury, P., Dwivedi, B.N. Periodicities of Sunspot Number and Coronal Index Time Series During Solar Cycle 23. Solar Physics 270, 365, 2011. (doi)
  • Chowdhury, P., Choudhary, D.P., Gosain, S. A Study of the Hemispheric Asymmetry of Sunspot Area during Solar Cycles 23 and 24. The Astrophysical Journal 768, article id. 188, 2013. (doi)
  • Chowdhury, P., Choudhary, D.P., Gosain, S., Moon, Y.-J. Short-term periodicities in interplanetary, geomagnetic and solar phenomena during solar cycle 24. Astrophysics and Space Science 356, 7, 2015. (doi)
  • Chowdhury, P., Kudela, K., Moon, Y.-J. A Study of Heliospheric Modulation and Periodicities of Galactic Cosmic Rays During Cycle 24. Solar Physics 291, 581, 2016. (doi)
  • Clette, F. Past and future sunspot indices: New goals for SoTerIA. Journal of Atmospheric and Solar-Terrestrial Physics 73:182–186, 2011. (doi)
  • Clette, F., Lefèvre, L. Are the sunspots really vanishing? Anomalies in solar cycle 23 and implications for long-term models and proxies. Journal of Space Weather and Space Climate 2, article id. A06, 2012. (doi)
  • Clette, F., Svalgaard, L., Vaquero, J.M., Cliver, E.W. Revisiting the Sunspot Number. A 400-Year Perspective on the Solar Cycle. Space Science Reviews 186, 35, 2014. (doi)
  • Clette, F., Cliver, E.W., Lefèvre, L., Svalgaard, L., Vaquero, J.M. Revision of the Sunspot Number(s). Space Weather 13, 529, 2015. (doi)
  • Clette, F., Berghmans, D., Vanlommel, P., van der Linden, R.A.M., Koeckelenbergh, A., and Wauters, L. From the Wolf number to the International Sunspot Index: 25 years of SIDC. Advances in Space Research, 40:919–928, 2007. (doi)
  • Cliver, E.W., Ling, A.G. 22 Year Patterns in the Relationship of Sunspot Number and Tilt Angle to Cosmic-Ray Intensity. The Astrophysical Journal 551, L189, 2001. (doi)
  • Cliver, E.W., Clette, F., Svalgaard, L. Recalibrating Sunspot Number (SSN): The SSN Workshops. Cent. Eur. Astrophys. Bull. 37:401-416, 2013. (pdf)
  • Cliver, E.W., Clette, F., Svalgaard, L., Vaquero, J.M. Recalibrating the Sunspot Number (SN): The 3rd and 4th SN Workshops. Central European Astrophysical Bulletin 39, 1, 2015.
  • Cristo, A., Vaquero, J.M., Sánchez-Bajo, F. HSUNSPOTS: a Tool for the Analysis of Historical Sunspot Drawings. Journal of Atmospheric and Solar-Terrestrial Physics 73:187-190, 2011. (doi)
  • Curto, J.J., Blanca, M., Martínez, E. Automatic Sunspots Detection on Full-Disk Solar Images using Mathematical Morphology. Solar Physics 250, 411, 2008. (doi)
  • Dasi-Espuig, M., Jiang, J., Krivova, N.A., Solanki, S.K., Unruh, Y.C., Yeo, K.L. Astronomy & Astrophysics 590, article id. A63, 2016. (doi)
  • Deng, L.H., Li, B., Zheng, Y.F., Cheng, X.M. Relative phase analyses of 10.7 cm solar radio flux with sunspot numbers. New Astronomy 23, 1, 2013. (doi)
  • Deng, L.H., Qu, Z.Q., Yan, X.L., Wang, K.R. Phase analysis of sunspot group numbers on both solar hemispheres. Research in Astronomy and Astrophysics 13, 104, 2013. (doi)
  • Deng, L.H., Xiang, Y.Y., Qu, Z.N., An, J.M. Systematic Regularity of Hemispheric Sunspot Areas Over the Past 140 Years. The Astronomical Journal 151, article id. 70, 2016. (doi)
  • Dikpati, M., Gilman, P.A., de Toma, G. The Waldmeier Effect: An Artifact of the Definition of Wolf Sunspot Number? The Astrophysical Journal Letters 673, article id. L99, 2008. (doi)
  • Dikpati, M., Gilman, P.A., Kane, R.P. Length of a minimum as predictor of next solar cycle's strength. Geophysical Research Letters 37, article ID L06104, 2010. (doi)
  • Diercke, A., Arlt, R., Denker, C. Digitization of sunspot drawings by Spörer made in 1861–1894. Astronomische Nachrichten 336, 53, 2015. (doi)
  • Du, Z.L. Relationship Between Solar Maximum Amplitude and Max-Max Cycle Length. The Astronomical Journal 132, 1485, 2006. (doi)
  • Du, Z., Du, S. The Relationship Between the Amplitude and Descending Time of a Solar Activity Cycle. Solar Physics 238, 431, 2006. (doi)
  • Du, Z., Wang, H., Zhang, L. Correlation Function Analysis between Sunspot Cycle Amplitudes and Rise Times. Solar Physics 255, 179, 2009. (doi)
  • Du, Z. The Shape of Solar Cycle Described by a Modified Gaussian Function. Solar Physics 273, 231, 2011. (doi)
  • Du, Z.L. The Solar Cycle: a new prediction technique based on logarithmic values. Astrophysics and Space Science 338, 9, 2012. (doi)
  • Erofeev, D. The Relationship Between Solar Activity and the Large-Scale Axisymmetric Magnetic Field. Solar Physics 198, 31, 2001. (doi)
  • Erwin, E. H., Coffey, H.E., Denig, W.F., Willis, D.M., Henwood, R., Wild, M.N. The Greenwich Photo-heliographic Results (1874 - 1976): Initial Corrections to the Printed Publications. Solar Physics 288, 157, 2013. (doi)
  • Faria, H.H., Echer, E., Rigozo, N.R., Vieira, L.E.A., Nordemann, D.J.R., and Prestes, A.A comparison of the spectral characteristics of the Wolf Sunspot Number (RZ) and Group Sunspot Number (RG). Solar Physics, 223:305–318, 2004. (doi)
  • Feulner, G. Erratum to: On the Relation Between Solar Activity and Clear-Sky Terrestrial Irradiance. Solar Physics 283, 719, 2013. (doi)
  • Feynman, J., Ruzmaikin, A. The Sun’s Strange Behavior: Maunder Minimum or Gleissberg Cycle? Solar Physics 272, 351, 2011. (doi)
  • Fligge, M., Solanki, S.K., Beer, J. Determination of solar cycle length variations using the continuous wavelet transform. Astronomy and Astrophysics 346, 313, 1999.
  • Foukal, P. An Explanation of the Differences Between the Sunspot Area Scales of the Royal Greenwich and Mt. Wilson Observatories, and the SOON Program. Solar Physics 289, 1517, 2014. (doi)
  • Foukal, P. Dimming of the Mid-20th Century Sun. The Astrophysical Journal 815, article id. 9, 2015. (doi)
  • Frick, P., Galyagin, D., Hoyt, D.V., Nesme-Ribes, E., Schatten, K.H., Sokoloff, D., Zakharov, V. Wavelet analysis of solar activity recorded by sunspot groups. Astronomy and Astrophysics 328, 670, 1997.
  • Galaviz, P., Vaquero, J.M., Gallego, M.C., Sánchez-Bajo, F. A small collection of sunspot drawings made in the Royal Astronomical Observatory of the Spanish Navy in 1884. Advances in Space Research 58, 2247, 2016. (doi)
  • Gao, P.X. Long-term Trend of Sunspot Numbers. The Astrophysical Journal 830, article id. 140, 2016. (doi)
  • Getko, R. Statistics of sunspot group clusters. Journal of Space Weather and Space Climate 3, article id. A09, 2013. (doi)
  • Gibson, S.E., Kozyra, J.U., de Toma, G., Emery, B.A., Onsager, T., Thompson, B.J. If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals. Journal of Geophysical Research: Space Physics 114, article ID A09105, 2009. (doi)
  • Gil-Alana, L.A. Time Series Modeling of Sunspot Numbers Using Long-Range Cyclical Dependence. Solar Physics 257, 371, 2009. (doi)
  • Gkana, A., Zachilas, L. Re-evaluation of Predictive Models in Light of New Data: Sunspot Number Version 2.0. Solar Physics 291, 2457, 2016. (doi)
  • Goelzer, M.L., Smith, C.W., Schwadron, N.A., McCracken, K.G. An analysis of heliospheric magnetic field flux based on sunspot number from 1749 to today and prediction for the coming solar minimum. Journal of Geophysical Research: Space Physics 118, 7525, 2013. (doi)
  • Gómez, J.M., Vaquero, J.M. The sunspot observations by Rheita in 1642. The Observatory 135, 220, 2015.
  • Gonçalves, R., Pinto, A.A., Stollenwerk, N. Cycles and Universality in Sunspot Number Fluctuations. The Astrophysical Journal 691, 1583, 2009. (doi)
  • Greenkorn, R.A. Analysis of Sunspot Activity Cycles. Solar Physics 255, 301, 2009. (doi)
  • Greenkorn, R.A. A Comparison of the 10.7-cm Radio Flux Values and the International Sunspot Numbers for Solar Activity Cycles 19, 20, and 21. Solar Physics 280, 205, 2012. (doi)
  • Haigh, J.D. The Sun and the Earth's Climate. Living Reviews in Solar Physics 4, article id.2, 2007. (doi)
  • Hanslmeier, A., Denkmayr, K., Weiss, P. Longterm Prediction of Solar Activity Using the Combined Method. Solar Physics 184, 213, 1999. (doi)
  • Harvey, K.L., White, O.R. What is solar cycle minimum? Journal of Geophysical Research: Space Physics 104, 19759, 1999. (doi)
  • Hathaway, D.H., Wilson, R.M., Reichmann, E.J.    A Synthesis of Solar Cycle Prediction Techniques. Journal of Geophysical Research 104, 375, 1999. (doi)
  • Hathaway, D.H., Wilson, R.M., Reichmann, E.J., Group sunspot numbers: Sunspot cycle characteristics. Solar Physics, 211:357–370, 2002. (doi)
  • Hathaway, D.H., Wilson, R.M. What the Sunspot Record Tells Us About Space Climate. Solar Physics 224, 5, 2004. (doi)
  • Hathaway, D.H., Wilson, R.M. Geomagnetic activity indicates large amplitude for sunspot cycle 24. Geophysical Research Letters 33, article ID L18101, 2006. (doi)
  • Hathaway, D.H., Wilson, R.M. Geomagnetic activity indicates large amplitude for sunspot cycle 24. Geophysical Research Letters 33, article ID L18101, 2006. (doi)
  • Hathaway, D.H., Choudhary, D.P.   Sunspot Group Decay. Solar Physics 250, 269, 2008. (doi)
  • Hathaway, D.H. A Curious History of Sunspot Penumbrae. Solar Physics 286, 347, 2013. (doi)
  • Hathaway, D.H. The Solar Cycle. Living Reviews in Solar Physics 12, article id. 4, 2015. (doi)
  • Hempelmann, A., Weber, W. Correlation Between the Sunspot Number, the Total Solar Irradiance, and the Terrestrial Insolation. Solar Physics 277, 417, 2012. (doi)
  • Hossfield, C.H. A history of the Zurich and American relative sunspot number indices. Journal of the American Association of Variable Star Observers, 31:48–53, 2002. (ads)
  • Hoyng, P. Is the solar cycle timed by a clock? Solar Physics 169, 253, 1996. (doi)
  • Hoyt, D.V. and Schatten, K.H. A new look at Wolf sunspot numbers in the late 1700’s. Solar Physics, 138:387–397, 1992. (doi, ads)
  • Hoyt, D.V. and Schatten, K.H. New information on solar activity, 1779–1818, from Sir William Herschel’s unpublished notebooks. Astrophysical Journal, 384:361–384, 1992. (doi, ads)
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